Recommended · for some experience
EEVblog #70 - Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E (Hack)
Why people recommend it
EEVblog's walkthrough of unlocking a Rigol DS1052E to 100MHz bandwidth, cited when people weigh up which budget oscilloscope to buy.
Watch for: Older model; newer scopes may be the better buy